1) C-3P0's restraining bolt.
R2-D2's is taken off so Luke can play the message, but I never noticed when 3PO's is removed, or it just never crossed my mind to pay attention to it. It turns out that the bolt is removed between the time they leave the Jawa BBQ & the time they arrive in Mos Isley. This is a nice subtle little symbol. In fact, it's more subtle than I thought Lucas capable of. Once Luke finds Owen and Berue dead, he symbolically joins the Alliance. It is @ this point that he also "frees" C-3PO because the Rebel Alliance is one of peace and liberty. Nice job Luke.
2) Han calls Luke "Buddy"
Throughout most of the film Han refers to Luke as "Kid," but as they flee the Death Star, right after Obi-Wan is killed, Han calls him "Buddy." Here wee have a nice little rite of passage as Luke is no longer the innocent farm boy. He has become Han's equal, having witnessed the death of his mentor. This is much more jarring for him than the deaths of his aunt & uncle because he is now fighting for something & the death means more to him. Their deaths represented freedom; Obi-Wan's represents the moment when Luke becomes a "man." (Not to be confused w/ the 1st time he bangs his sister which must have happened some time between Empire & Jedi.)
3) Leia bangs Chewie
While we're on the subject of Leia sex, I found a little more legitimacy to her claim that she'd "rather kiss a Wookiee" than Han. After Han & Luke finish destroying the Tie-Fighters that chase them from the Death Star, they shout we did it & hug. The film then cuts to Leia & Chewie as she says the same thing & Leia & Chewie hug. I've always placed great importance on this hug, but only this time did I realize it's true meaning as I wondered what the Hell she did. She didn't work the guns, that was Han & Luke. She didn't angle the deflector shield or pilot the Falcon, that was Chewie. What gives her the right to claim to be part of this battle... she was just a passive observer like me & everyone else who views the action. It's exciting, but I don't think I can claim to have done anything in the battle (other than not changing the channel). Is this arrogant aristocrat hitching her wagon to the glories of a scruffy looking pirate & some Hitler youth farm boy? Certainly not. Then it hit me... what did she do w/ Chewie? IT! While Han & Luke are fighting the Empire, she & Chewbacca are in the "cock-pit" quietly humping... AWESOME!